Introduction to Center and Core Missions The Harvard Digestive Disease Center is focused on the cell biology and function of epithelial cells of the alimentary tract, liver, and pancreas; and how epithelial biology manifests itself in mucosal immunity and allergy, innate host defense, digestion and absorption, the development of gastrointestinal neoplasia, and the many other functions of the Gl tract. The Center aims to facilitate multidisciplinary research in this field by providing technical resources, core services, scientific expertise, and an important meeting point to foster close scientific and intellectual relationships among independent investigators in Harvard-affiliated hospitals, the Harvard Medical School and adjacent research institutions in the Longwood Medical Area. We also aim to recruit new and established investigators to the field. Our overarching mission is to foster better basic and translational science in fields related to digestive diseases by: connecting people, 'creating opportunity, and 'extending resources. Shared intellectual and scientific resources to enhance this effort and the productivity of our research base are provided by four service Cores and an Administrative Core (see Figure 1-CoreB). Each Core provides the following general resources to the HDDC: Core Services Materials and Reagents Instrumentation and Equipment Expertise, Protocols, and Training Core-development research Core B provides HDDC members with light and electron microscopy, resources, and scientific support essential for research in the digestive diseases.